feat: Force release for a specific library even if there are no releasable changes (#2181)

lqiu96 · JoeWang1127 · web-flow · commit 382e634dd1ef · 2025-09-18T14:14:09.000-04:00
Fixes: #2032 Changes: - Split updateLibrary's GetCommits functionality into a separate function for easier testing (inject commits directly without having to setup a repo) Logic: If a library is specified for release, force a release for it. Use the library version override if provided as the new version. If the override is not specified, report an error back to the user to use the version flag. --------- Signed-off-by: Lawrence Qiu <lawrenceqiu@google.com> Signed-off-by: Lawrence Qiu <lqiu96@gmail.com> Co-authored-by: Joe Wang <106995533+JoeWang1127@users.noreply.github.com>
diff --git a/internal/librarian/help.go b/internal/librarian/help.go
@@ -86,6 +86,12 @@ according to semver rules. It then delegates all language-specific file
 modifications, such as updating a CHANGELOG.md or bumping the version in a pom.xml,
 to the configured language-specific container.
 
+If a specific library is configured for release via the '--library' flag, a single
+releasable change is needed to automatically calculate a version bump. If there are
+no releasable changes since the last release, the '--version' flag should be included
+to set a new version for the library. The new version must be "SemVer" greater than the
+current version.
+
 By default, 'release init' leaves the changes in your local working directory
 for inspection. Use the '--push' flag to automatically commit the changes to
 a new branch and create a pull request on GitHub. The '--commit' flag may be
diff --git a/internal/librarian/release_init.go b/internal/librarian/release_init.go
@@ -132,7 +132,6 @@ func (r *initRunner) runInitCommand(ctx context.Context, outputDir string) error
 
 	src := r.repo.GetDir()
 	librariesToRelease := r.state.Libraries
-	// If a library has been specified, only process the release for it
 	if r.library != "" {
 		library := findLibraryByID(r.state, r.library)
 		if library == nil {
@@ -143,9 +142,10 @@ func (r *initRunner) runInitCommand(ctx context.Context, outputDir string) error
 	// Mark if there are any library that needs to be released
 	foundReleasableLibrary := false
 	for _, library := range librariesToRelease {
-		if err := r.updateLibrary(library); err != nil {
+		if err := r.processLibrary(library); err != nil {
 			return err
 		}
+
 		// Copy the library files over if a release is needed
 		if library.ReleaseTriggered {
 			foundReleasableLibrary = true
@@ -202,55 +202,66 @@ func (r *initRunner) runInitCommand(ctx context.Context, outputDir string) error
 	return copyGlobalAllowlist(r.librarianConfig, r.repo.GetDir(), outputDir, false)
 }
 
-// updateLibrary updates the given library in the following way:
-//
-// 1. Update the library's previous version.
-//
-// 2. Get the library's commit history in the given git repository.
-//
-// 3. Override the library version if libraryVersion is not empty.
-//
-// 4. Set the library's release trigger to true.
-func (r *initRunner) updateLibrary(library *config.LibraryState) error {
+// processLibrary wrapper to process the library for release. Helps retrieve latest commits
+// since the last release and passing the changes to updateLibrary.
+func (r *initRunner) processLibrary(library *config.LibraryState) error {
 	commits, err := GetConventionalCommitsSinceLastRelease(r.repo, library)
 	if err != nil {
 		return fmt.Errorf("failed to fetch conventional commits for library, %s: %w", library.ID, err)
 	}
+	return r.updateLibrary(library, commits)
+}
 
-	if len(commits) == 0 {
-		slog.Info("Skip releasing library as there are no commits", "library", library.ID)
-		return nil
-	}
-
-	nextVersion, err := r.determineNextVersion(commits, library.Version, library.ID)
-	if err != nil {
-		return err
+// updateLibrary updates the library's state with the new release information:
+//
+// 1. Determines the library version's next version.
+//
+// 2. Updates the library's previous version and the new current version.
+//
+// 3. Set the library's release trigger to true.
+func (r *initRunner) updateLibrary(library *config.LibraryState, commits []*conventionalcommits.ConventionalCommit) error {
+	var nextVersion string
+	// If library version was explicitly set, attempt to use it. Otherwise, try to determine the version from the commits.
+	if r.libraryVersion != "" {
+		slog.Info("Library version override inputted", "currentVersion", library.Version, "inputVersion", r.libraryVersion)
+		nextVersion = semver.MaxVersion(library.Version, r.libraryVersion)
+		slog.Debug("Determined the library's next version from version input", "library", library.ID, "nextVersion", nextVersion)
+		// Currently, nextVersion is the max of current version or input version. If nextVersion is equal to the current version,
+		// then the input version is either equal or less than current version and cannot be used for release
+		if nextVersion == library.Version {
+			return fmt.Errorf("inputted version is not SemVer greater than the current version. Set a version SemVer greater than current than: %s", library.Version)
+		}
+	} else {
+		var err error
+		nextVersion, err = r.determineNextVersion(commits, library.Version, library.ID)
+		if err != nil {
+			return err
+		}
+		slog.Debug("Determined the library's next version from commits", "library", library.ID, "nextVersion", nextVersion)
+		// Unable to find a releasable unit from the changes
+		if nextVersion == library.Version {
+			// No library was inputted for release. Skipping this library for release
+			if r.library == "" {
+				slog.Info("Library does not have any releasable units and will not be released.", "library", library.ID, "version", library.Version)
+				return nil
+			}
+			// Library was inputted for release, but does not contain a releasable unit
+			return fmt.Errorf("library does not have a releasable unit and will not be released. Use the version flag to force a release for: %s", library.ID)
+		}
+		slog.Info("Updating library to the next version", "library", r.library, "currentVersion", library.Version, "nextVersion", nextVersion)
 	}
 
 	// Update the previous version, we need this value when creating release note.
 	library.PreviousVersion = library.Version
 	library.Changes = commits
-	// Only update the library state if there are releasable units
-	if library.Version != nextVersion {
-		library.Version = nextVersion
-		library.ReleaseTriggered = true
-	}
-
+	library.Version = nextVersion
+	library.ReleaseTriggered = true
 	return nil
 }
 
+// determineNextVersion determines the next valid SemVer version from the commits or from
+// the next_version override value in the config.yaml file.
 func (r *initRunner) determineNextVersion(commits []*conventionalcommits.ConventionalCommit, currentVersion string, libraryID string) (string, error) {
-	// If library version explicitly passed to CLI, use it
-	if r.libraryVersion != "" {
-		slog.Info("Library version override specified", "currentVersion", currentVersion, "version", r.libraryVersion)
-		newVersion := semver.MaxVersion(currentVersion, r.libraryVersion)
-		if newVersion == r.libraryVersion {
-			return newVersion, nil
-		} else {
-			slog.Warn("Specified version is not higher than the current version, ignoring override.")
-		}
-	}
-
 	nextVersionFromCommits, err := NextVersion(commits, currentVersion)
 	if err != nil {
 		return "", err
diff --git a/internal/librarian/release_init_test.go b/internal/librarian/release_init_test.go
